jquery method to select at least one item for a group of checkbox

<div class="form-input" id="stopStatus">
  <label><input type="checkbox" name="SSStatus" id="SSStatus">保</label>
  <label><input type="checkbox" name="SGStatus" id="SGStatus">障</label>
  <label><input type="checkbox" name="PFStatus" id="PFStatus">金</label>
</div>

var checkboxObj = $ ("# stopStatus"). find ("input [type = checkbox]: checked" );
 if (checkboxObj.size () == 0 ) { 
   dialog ( "Select at least one item!", 0 )
    return  false ; 
   }